The subject matter herein relates generally to electrical connectors that are configured to transmit data signals.
Electrical connectors may be used within communication systems, such as telecommunication equipment, servers, data storage, transport devices, and the like. Some communication systems include daughter card assemblies, which may be communicatively coupled to each other through a backplane (or midplane) assembly. Each of the daughter card assemblies includes a receptacle connector that is mounted to a circuit board, which is referred to as a daughter card. The backplane assembly includes header connectors that are mounted to the backplane (or midplane) circuit board. Each of the receptacle connectors of the daughter card assemblies mates with a different one of the header connectors thereby communicatively coupling the daughter card assemblies to the backplane assembly.
The receptacle connector includes a mating side that engages the backplane assembly and a mounting side that is mounted to the corresponding circuit board. The mating and mounting sides typically face in directions that are perpendicular to each other. In many connectors, the mating and mounting sides have a dense array of contacts that include signal contacts and ground contacts.
The daughter card to which the receptacle connector is mounted includes an array of plated thru-holes that receive the signal and ground contacts of the receptacle connector. The plated thru-holes that receive the signal contacts are electrically connected to signal traces of the circuit board. Many circuit boards include multiple signal layers in which each signal layer has a number of signal traces. The signal traces of different layers are joined through vias in the layers. Accordingly, a signal propagating along a signal pathway in the circuit board may encounter a number of interfaces where the vias of signal layers electrically join different signal traces. Generally, increasing the number of such interfaces along the signal pathway increases signal degradation (or loss in signal quality).
One ongoing trend in electrical connectors, including the receptacle connectors discussed above, is the increased density of signal pathways through the electrical connector. Greater densities permit smaller devices and/or enable greater data throughput. To accommodate the greater density of signal pathways in the receptacle connectors, the circuit boards to which the receptacle connectors are mounted have been modified. For example, signal layers have been added to the circuit boards to provide more space for routing the signal pathways to or from the plated thru-holes. As discussed above, however, additional signal layers correspond to more interfaces that are encountered by the propagating signal, which can negatively affect signal quality. Increasing the number of layers also increases the cost of the circuit board.
In addition to the above, one drawback with conventional daughter card assemblies is that the receptacle connectors have a fixed geometry that provides only a single mounting array that is mounted to a single daughter card. Receptacle connectors capable of mounting to multiple daughter cards, in addition to coupling to the header connector, may be desired. For example, a receptacle connector with two mounting arrays could be mounted to two daughter cards. Such receptacle connectors could possibly reduce the contact densities of the mounting arrays so that thinner daughter cards may be used while also maintaining the overall throughput of the receptacle connector.
Accordingly, there is a need for an electrical connector having multiple mounting arrays that is capable of being communicatively coupled to three circuit boards.